Measuring Lactate Threshold without being pricked? BSX Insight

I have a love/hate relationship with the latest technology. On one hand, the science geek in me loves all of the latest gadgets. I have a make shift lab of gadgets in my house. I’ve got all the acronyms you could dream of, including a few make shift EMG and EEG devices, GSR, HRV, and you name it. I love experimenting with and figuring out ways to measure the bodies response and adaptation to training.

On the other hand, I’m a skeptic to the practical application of many of the same gadgets that the science nerd in me loves. Why? Because often their practical application to coaching is limited. Yes, they can give some really cool data, and perhaps confirm some theories, but from a practical standpoint they don’t often translate. It doesn’t enact meaningful change for the most part. As coaches, we don’t alter anything we are doing because of the data.

This inner struggle then is to find measurables that enact meaningful change. In my own coaching, I’ve used lactate tests to this effect. It’s a little expensive and a tad invasive, but it still provides some good data when used every once in a while. If used correctly, you get a good snapshot of the aerobic and anaerobic profile of a runner.

So when I stumbled across a new company, BSX athletics, that was claiming to be able to measure the lactate threshold, non-invasively, I was intrigued, but skeptical. My initial reaction was that it wasn’t possible (yet..) with technology and that there had to be some sort of catch.

BSX Insight

Being that they were in Houston, I reached out and they were gracious enough to let me stop by and check out what they had to offer.

How do they do it?
The simple answer is NIRS (Near-Infrared Spectroscopy). They use NIRS to find tissue Oxygenation. It works via sending light into the tissue and then measuring the light as it bounces back to the device. From here, you can get a measurement of the percentage of hemoglobin that has oxygen attached to it, or in scientific terms you get the percent tissue oxygen saturation (St02). While it sounds a bit perplexing to those who aren’t familiar with the technology, it’s been used for a few years in the scientific world (Review here)

What BSX did, was take things a step further. Instead of simply measuring tissue oxygenation, they asked what does this mean and what can it really tell us. In the next step, BSX, decided to see if they could use tissue oxygenation and combine it with a few other parameters they could measure using NIRS to measure something like lactate. What they found was that tissue oxygenation correlated well with lactate levels.

What BSX has done since this proof of concept is cleaned up and refined the data and started using statistical models to help refine the data. In their refinement process, they’ve tested over 250 people with traditional lactate threshold tests.

Too good to be true?As a scientists, I can practically hear you screaming, but is it accurate? That’s the key to all of this. According to BSX data, through those 250 tests they are up to 95% accuracy comparing what the BSX insight found for the lactate threshold and what traditional finger prick lactate measuring devices found for LT. Through the next few months they are increasing their testing numbers up to 600-750 and anticipate getting up to 97% accuracy.

What is kind of cool about the device is that while wearing it, it can relay the info to your garmin or other ANT+ watch essentially how close you are running to your LT. So it can be programmed to inform an athlete or speed up or slow down depending on where you are supposed to be running in terms of your %LT. For all of us college or high school coaches who have all too often sent a runner out on a threshold or tempo run only to have them go out too hard and blow up, this information could be incredibly valuable. I like to think of it as “overtraining insurance” for threshold runs and could definitely see myself using this as a learning device in that regards.

With NIRS, one of the issues you struggle with is keeping a good and constant signal. This is an inherent problem with any device that goes on a muscle during a variable movement activity like running. BSX seems to have solved this by using the calf muscle, and a calf-compression sleeve to hold the device in place without shifting. While it might not seem like a big deal, for anyone who has worn wearable monitoring devices, I’ve got to say I love their solution to the problem.

One of the possible downsides right now is that you have to do the initial calibration by simply running a progressive treadmill test with the device on. It’s not a huge downside, but for some treadmill running is torturous. The reason for this is to eliminate the large pacing variability this often occurs when doing an outside test.If they can eventually figure out how to break away from using a set standardized treadmill test to give LT, it would take this device to the next level.

In addition to giving a LT readout, they also can measure heart rate, cadence, and pace with the device. In discussions with them, they had ideas of including a few other parameters in the future. To me, if you could include tissue oxygenation readouts and perhaps correlated lactate levels, that would be intriguing for the science nerds of us, though not as easily usable as the LT numbers for regular athletes.

So what?

BSX is a very intriguing device. The accuracy level they have reached and the amount of research that has gone into the device is impressive. Combine that with the very low price point for NIRS technology, and to me it’s a no brainer to try out. Whether it breakthrough into a device that goes beyond your science/gadgets for coaches will remain to be seen, but it certainly has more promise than any device I’ve seen in years. The guys in charge are on the right track and have the goal in mind to make it usable for athletes and coaches. It’s not meant to be another device that gives us data that does nothing to actually alter our training. At the very least, I can’t wait to get my hands on a device and see what it has to offer.

Very interesting device.I was wondering whether it would not be better to put it on the arm triceps. After all the lactate level should be same, since when measuring it directly they take it from the an ear lobe or a finger.

Assuming this device works as intended, how do you envision you would use it? Use workouts that ask a runner to work at a specific lactate concentration instead of pace (which can be variable on trails or non flat roads)? Would this not be a lagging output indicator like heart rate?

This will not work when exercising in the heat or during hyperthermia. We are doing some work with the DoD which we use a NIRS device during simulated hemorrhage during heat stress. We have a publication in press in the American Journal of Physiology with the results of this device currently. Because of an increase in skin blood flow, the tissue O2 saturation may also include that value in combined with muscle O2 saturation. In the lab during thermoneutral environments it may work, but in the field under hot environmental, it may not do what they want it to.